IMPORTANT: In July 2025, we stopped releasing new versions of KTX modules, and we removed the KTX libraries from the Firebase Android BoM (v34.0.0). If you use KTX APIs from the previously released KTX modules, we recommend that you migrate your app to use KTX APIs from the main modules instead. For details, see the FAQ about this initiative.

PhoneAuthOptions.Builder

class PhoneAuthOptions.Builder

A Builder class for PhoneAuthOptions. Get an instance of this Builder using newBuilder or newBuilder.

Summary

Public constructors
`Builder(auth: FirebaseAuth)` Creates a new Builder

Public functions
`PhoneAuthOptions`	`build()` Returns the `PhoneAuthOptions` that this `Builder` has constructed.
`PhoneAuthOptions.Builder`	`requireSmsValidation(requireSmsValidation: Boolean)` Specifies whether to force an SMS to be sent for second factor validation.
`PhoneAuthOptions.Builder`	`setActivity(activity: Activity)` Sets the `Activity` to which the callbacks are scoped, and with which app verification will be completed.
`PhoneAuthOptions.Builder`	`setCallbacks( callbacks: PhoneAuthProvider.OnVerificationStateChangedCallbacks )` Sets the callbacks to get the status of phone number verification.
`PhoneAuthOptions.Builder`	`setForceResendingToken( forceResendingToken: PhoneAuthProvider.ForceResendingToken )` Sets the `ForceResendingToken` to force another verification SMS to be sent before the auto-retrieval timeout.
`PhoneAuthOptions.Builder`	`setMultiFactorHint(phoneMultiFactorInfo: PhoneMultiFactorInfo)` Sets the `PhoneMultiFactorInfo` to use for second factor sign-in.
`PhoneAuthOptions.Builder`	`setMultiFactorSession(multiFactorSession: MultiFactorSession)` Sets the `MultiFactorSession` that holds the necessary data to start an SMS verification for multi-factor authentication enrollment or sign in.
`PhoneAuthOptions.Builder`	`setPhoneNumber(phoneNumber: String)` Sets the phone number for sign-in, sign-up, or second factor enrollment.
`PhoneAuthOptions.Builder`	`setTimeout(timeout: Long, unit: TimeUnit)` Sets the maximum amount of time you are willing to wait for SMS auto-retrieval to be completed by the library.

Public constructors

Builder

Builder(auth: FirebaseAuth)

Creates a new Builder

Parameters
`auth: FirebaseAuth`	the `FirebaseAuth` with which this Builder is associated.

Public functions

build

fun build(): PhoneAuthOptions

Returns the PhoneAuthOptions that this Builder has constructed.

requireSmsValidation

fun requireSmsValidation(requireSmsValidation: Boolean): PhoneAuthOptions.Builder

Specifies whether to force an SMS to be sent for second factor validation.

In some cases the phone number can be instantly verified without needing to send or enter a verification code. This feature can be disabled here, and it is enabled by default.

This is only applicable to Multi-Factor Authentication.

setActivity

fun setActivity(activity: Activity): PhoneAuthOptions.Builder

Sets the Activity to which the callbacks are scoped, and with which app verification will be completed. This is an optional parameter of the builder, but is required to perform a reCAPTCHA fallback for client verification. If the activity is not set and a reCAPTCHA verification is attempted, a FirebaseAuthMissingActivityForRecaptchaException error is thrown, which can be handled in the onVerificationFailed callback.

setCallbacks

fun setCallbacks(
    callbacks: PhoneAuthProvider.OnVerificationStateChangedCallbacks
): PhoneAuthOptions.Builder

Sets the callbacks to get the status of phone number verification. The callbacks will be automatically removed when the specified activity has stopped.

When a test phone number and SMS code pair is set via setAutoRetrievedSmsCodeForPhoneNumber and in the Firebase console, onCodeAutoRetrievalTimeOut will never be triggered.

setForceResendingToken

fun setForceResendingToken(
    forceResendingToken: PhoneAuthProvider.ForceResendingToken
): PhoneAuthOptions.Builder

Sets the ForceResendingToken to force another verification SMS to be sent before the auto-retrieval timeout.

setMultiFactorHint

fun setMultiFactorHint(phoneMultiFactorInfo: PhoneMultiFactorInfo): PhoneAuthOptions.Builder

Sets the PhoneMultiFactorInfo to use for second factor sign-in.

setMultiFactorSession

fun setMultiFactorSession(multiFactorSession: MultiFactorSession): PhoneAuthOptions.Builder

Sets the MultiFactorSession that holds the necessary data to start an SMS verification for multi-factor authentication enrollment or sign in.

When this is set, the verification will be for validating ownership of a phone SMS second factor, not for phone authentication.

setPhoneNumber

fun setPhoneNumber(phoneNumber: String): PhoneAuthOptions.Builder

Sets the phone number for sign-in, sign-up, or second factor enrollment.

Parameters
`phoneNumber: String`	a phone number that conforms to the E.164 format.

setTimeout

fun setTimeout(timeout: Long, unit: TimeUnit): PhoneAuthOptions.Builder

Sets the maximum amount of time you are willing to wait for SMS auto-retrieval to be completed by the library.

The minimum timeout is 30 seconds, and the maximum timeout is 2 minutes. If you specified a positive value less than 30 seconds, library will default to 30 seconds. Specifying a negative timeout or a timeout that is greater than 120 seconds will result in an being thrown.

Use 0 to disable SMS-auto-retrieval. This will also cause onCodeAutoRetrievalTimeOut to be called immediately.

Parameters
`timeout: Long`	the length of the timeout in the units specified by `unit`.
`unit: TimeUnit`	the `TimeUnit` for the `timeout`.